Method of assembling sheet metal parts



Feb. 10, 1948. w. H. POWERS E 2,435,697

.METHOD OF ASSEMBLING SHEET METAL PARTS I Original Filed March 24, 1941 INVENQR JJ/d/er /25 7511/6211 ATTORNE.

in particular, provides improved Patented Feb. 1b, 194s METHOD oF AssEMBLING SHEET METALPARTS Walter H. Powers, Jackson, Mich., assignor to Walker Manufacturing Company of Wisconsin, Racine, Wis., a corporation of Wisconsin Original application March 24, 1941, Serial No.

384,791, now PatentNo. 2,357,791,` dated September 5, 1944. Divided and this application November 6, 1943, Serial No. 509,263

l 4 Claims.

. 1 The present invention relates to silencers. and

methods of assembling sheet metal parts. f

The present application isa division of vapplicants copending applicatiomserial No. 384.791, filed March 24, "1,941, now Patent No. 2,357,791, granted September 5, 1944. y

The vprincipal object of the present invention is Lto' provide 1an improved method for-forming a connection between a tubular member and a partition, the tubular memberbeing provided with radially outwardly extending projections, which method is principally'characterized by providing Athe partition member with a conical neck which, in assemblyis ironed by the projections, thereby giving it a shape which adapts it for final connection to the tubular member. 1

With the above as well asl other objects in view, which' appear in the following description and in the appended claims, a preferred butillustrative embodiment of the invention is shown in the accompanying drawing, throughout the several Fig. 4 is an enlarged view taken along the line f f 4--4 of Fig. 3; and I Fig. 5 is a fragmentary view taken along the line 55of Fig. 4.' f

It will be appreciated from a complete under standing of the inventiont'nat the improvements hereof mayA be utilized in thel manufacture of many different structureaintended. for widely differing purposes. By'wa'y of illustration of pre'- ferred embodiments; the present improvements are herein .illustrated in connection with the manufacture of silencers specifically designed for automotive service.

The general construction of the illustrative automotive silencer shown in the drawings, is described in detail,l and claimed, in the aforesaid Patent No.2,357,79'1.

lFor purposes of the present application, it is noted that the silencer comprises generally a cylindrlcal outer Vshell 250, which is provided with end heads 262 and 264. Head 262 is apertured (Cl. Ztl- 157) I i212, the end whereof is connected tothe-outlet 40. Outlet 40 in turn is adapted for connection to the tall pipe of the associated automobile.

The space between partition 216 and 264 con--V stitutes a resonator chamber, access to which is -Outlet conduit 212 is provided with a series of small resonator chambers which are dened by an intermediate shell 296, through which conduit 212 passes, and a series of partitions 214 and 298. These small chambers are designated 294, and access thereto is afforded by the series of small louver openings 213 in conduit 212.v Y,

. The invention is primarily concernedin the lllustrated embodiment, with the assembly of partitions such as 214, on the conduit 212, and be- 'fore proceeding to a description of this improved method, the operation of the illustrated silencer may briefly be described as follows.

The gas stream enters through the inlet 36and passes out through the outlet 40. In traversing the silencer, the stream is acted upon by the main resonator 282, the expansion chamber 280, and the small resonator chambers 294 which, in large part, eliminate the pressure peaks in the pulsating 'exhaust stream, and, consequently, in large part, silences the stream. l

`As most clearly appears in Figure 3, the louvers 213 in the conduit 212 are of the tangential form described and claimed in Gunn Patent No. 1,949,074. These louvers are arranged in axially spaced and circumferentially oiiset ring-like rows, the individual louvers in alternate rows being aligned with each other axially of the conduit. As aforesaid, these small louver openings'afford the acoustic coupling betweenthe interior vof the conduit 212 and the small chambers 294. The partition 214, and similar commentsfapply to the partitions 298. is provided with a neck 215 of conical form, the portion of largest diameter thereof being adjacent the junction between the neck and the body of the partition. The diameter of this largest portion is preferably substantially equal to the diameter of the imaginary surface including the crests of the louvers 213. t isprovided between each portion of largest diameter and the tube 212, which enables the partition in question to be fitted over the louver tube without deforming the individual louvers.

louvers to deform each neck portion of minimum diameter from its initial circular shape into a polygonal shape, the number of sides of which is equal to the number of louvers in two successive rings of such louvers. The difference between the minimum and maximum diameters is such that this deforming or ironing effect brings the sur- -face of the neck in the region of the small end thereof more nearly into contact with or immediately adjacent thefbody of the tube than would otherwise be the case, and materially facilitates the completion of the connection between each neck and the tube.

It will be noticed that the length of each neck is preferably approximately equal to the spacing, axially of the louver tube, between two aligned rings of louvers. The nal positioning of the partition is preferably such that the neck portion of 'largest diameter rests upon the louvers in one of such rings, thus bringing the portion of smallest diameter into registry with theV other such ring. The connection between each partition and the louver tube is preferably made by effecting a series, of welds between the tube and the neck portion. Preferably, also, such welds are made .adjacent the small end of each neck, and one such weld-is kmade in the space between successive louvers in the corresponding louver ring. Manufacturing variations may be expected to cause some variation in the exact point at which each such weld is made. In a general sense it has been foundV that the connection is satisfactory if the welds are made anywhere between the crest f one such engaged louver and the crest ofthe next successive louver in the same ring. Preferably, and as illustrated in Fig. 3, however, the welds are-made approximately midway between the crest of one such engaged louver and the ,crest of a louver in the next successive ring of louvers. An additional weld is also preferably made inj the region of Athe rolled seam 212a.

The individualwelds form a positiveconnection between eachepartition and the tube which secures the-'two together as a unit, and also serves to minimize any leakage space between the surfaceV of each tube and the neck. Any such leakage spaces which are not eliminated by the Vwelding operations are found -to have only a-negligible effect, if any, upon the performance of the silencer.

As willbe understood, the described arrangement'is particularly advantageous because it enables a 'given-louver tube construction to be utilized in building up a silencer having differing numbersiand differing sizes of chambers 294. This-is-because the individual partitions, such as 298, can be secured to the louver tube at am7 of a plurality of points along the body thereof. v What is claimed is :l Y

1. The method of'rforming a connection be.- tweenga -condui-thaving a series-of axiallyand Thisiitting operation, however, causes the indvidual With this relation, a relatively snug slip circumferentially distributed openings in the wall thereof, each opening being defined by a louver portion, the crest whereof projects radially outwardly from the surface of the conduit, and a partition or like member which comprises providing the partition with a neck of conical form, the diameter of the larger portion whereof is approximately equal to the diameter of the imaginaryv surface which includes said crests and the diameter of the smaller portion whereof is in excess of the diameter of said conduit, telescoping said neck and conduit together so that the ironing effect of the louvers deforms the portion of smaller diameter into a polygonal shape, and forming one ormore connections between the conduit and the neck, each said connection being made in the region of the portion ofsmal-ler diameter.

2. The method of forming a connection between a conduit having a series of axially and circumferentially distributed openings in the wall thereof,A each opening being defined by a louver portion, the crest whereof projects radially'outwardly from the surface of the conduit, and a partition'or like member which comprises providing the partition with a neck of conical form, the diameter of the larger portion whereof is approximately equal to the diameter of the imaginary surface which includes said crests and the diameter of the smaller portion whereof is in excess of the diameter of said conduit, telescopF ing said neck and conduit together so that the ironing effect of the louvers deforms the portion 0fy smaller diameter into a polygonalshape with at least certain ofthe polygonal sides-engaging the surface of the conduit, and forming one or more connections between the conduit and the neck, each said connection being made in the region of the portion of smaller diameter.

3, The method of forming a connection between a conduit having a series of axially and circumferentially distributed openings in the wall thereof, each opening being defined by a louver portion, the crest whereof projects radially outwardly from the surface of the conduit, and a partition or like member which comprises providing the `partition with a neck of conical form, the diameter of the larger portion whereof is approximately equal to the diameter of the imaginarysurface which includes said crests and the diameter of the smaller portion whereof is in excess of the diameter of said conduit, telescoping said neck and conduit together so that the ironing effect of the louvers deforms the portion of smaller diameterinto a polygonal shape with at least certain of the polygonal sides engaging the surface of the conduit, and forming one or more connections between the neck and the surface of the conduit.

4. The method of forming a connection between a conduit having. a series of axially and circumferentially distributed openings in the wall thereof, each opening being defined by a louver portion, the crest whereof projects radially outwardly from the surface of the conduit, and a partition or like member which comprises providing the partition with a neck of conical form, the diameter of the largerportion whereof -is approximately equal to the diameter of thev imaginary surface which includes said crests and the diameter of the smaller portion whereof is in excess of the diameter of said conduit, telescoping said neck and conduit together so that the ironing eiect of the louvers deforme the portion of smaller diameter into la polygonal shape. and. forming 5 6 one or more connections between the neck and Number Name Date the surface of the conduit. 2,251,880 Cary Aug. 5, 1941 WALTER H. POWERS. 1,949,074 Gunn Feb. 27, 1934 2,357,791 Powers Sept. 5, 1944 REFERENCES CITED 5 1,907,656 Oldberg May 9, 1933 1,272,581 Van Dorn July 16, 1918 l'hf fllligwlge'zferencee ale of record 1n the 1,781,297 Wysong *L Nov- 11 1930 1,091,462 Sandiford Mar. 24, 1914 UNITED STATES PATENTS Number Name Date lo 2,099,887 Heath Nov. 23, 1937 

